1. Field of the Invention
The present invention relates to a fuel cell system including a fuel cell stack comprising a stack body formed by stacking a plurality of power generation cells in a stacking direction, end plates provided at opposite ends of the stack body in the stacking direction, and power collecting terminals protruding outwardly from the end plates. The power generation cell includes an electrolyte electrode assembly and a separator. The electrolyte electrode assembly includes a pair of electrodes and an electrolyte interposed between the electrodes.
2. Description of the Related Art
For example, a polymer electrolyte fuel cell employs an electrolyte membrane (electrolyte). The electrolyte membrane is a polymer ion exchange membrane. A membrane electrode assembly (electrolyte electrode assembly) includes an anode, a cathode, and the electrolyte membrane interposed between the anode and the cathode. The membrane electrode assembly and separators sandwiching the membrane electrode assembly make up a unit of a fuel cell (power generation cell) for generating electricity. In use of the polymer electrolyte fuel cell, a predetermined number of power generation cells are stacked together to form a fuel cell stack.
In the fuel cell stack, normally, terminal plates, insulating plates, and end plates are provided at opposite ends of a stack body formed by stacking a plurality of power generation cells in the stacking direction. The terminal plates have power collecting terminals for collecting electrical energy from the stack body to the outside. The power collecting terminals are connected to a contactor (or a relay) for implementing the ON/OFF control for supplying electrical energy to an external load such as a motor.
For example, in a terminal device of a fuel cell disclosed in Japanese Laid-Open Utility Model Publication No. 61-7868, as shown in FIG. 10, unit cells 1 and bipolar plates 2 are stacked alternately, and half plates 2a are provided at opposite ends in the stacking direction. Terminal plates 3 are provided outside the half plates 2a, and insulating plates 4 are provided outside the terminal plates 3. Further, end plates 5 are provided outside the insulating plates 4.
An electrode pole (power collecting terminal) 6 is electrically connected to each of the terminal plates 3. The electrode pole 6 passes through the insulating plate 4 and the end plate 5 to the outside. The electrode pole 6 is inserted into an insulating sleeve 7, and fixed using a nut 8. A high voltage cable 9 is connected to the electrode pole 6. The cable 9 is connected to a contactor (not shown) or the like.
Due to the constraint with the layout, devices such as the contactor may be provided at one end of the fuel cell stack in the stacking direction. In this case, the cable 9 connected to the electrode pole 6 protruding outwardly from each end plate 5 needs to be drawn to the one side in the stacking direction.
For this purpose, the cable 9 connected to the electrode pole 6 at the other end in the stacking direction is curved at an angle of substantially 180°, and turns back toward the one end in the stacking direction. Thus, the cable 9 protrudes from the end surface of the end plate 5 by a relatively large distance H in the direction indicated by the arrow A.
Thus, a space required for placing the entire fuel cell stack becomes considerably large. Therefore, in particular, the fuel cell stack cannot be placed in a small space of a vehicle. Further, the layout cannot be designed freely.